altbeton

Altbeton is a term used in German-speaking contexts to describe concrete that has reached the end of its service life and is removed during demolition. The concept also encompasses the processing and reuse of demolished concrete as recycled material for new construction. In practice, Altbeton often refers to concrete from buildings, bridges, and other structures that is crushed and sorted for further use.

When demolished, concrete is typically processed into recycled concrete aggregate (RCA). This material may consist of concrete rubble with or without residual cement paste, and it is further cleaned and graded by size. Reinforcement steel is usually removed, and the remaining material is tested for properties such as particle size distribution, strength potential, absorption, and impurities. RCA can then be used as a partial or full substitute for natural aggregates in new concrete or as a base or sub-base material for roads and foundations, depending on local regulations and project requirements.

Environmental and regulatory aspects emphasize waste reduction, resource conservation, and lower landfill use. The use of Altbeton aligns with sustainability goals, but it requires adherence to standards governing aggregates and concrete, such as regional or international codes for recycled materials, durability considerations, and suitability for structural applications.

Challenges include variability in composition, presence of contaminants, potential alkali-silica reactions, and the need for consistent quality control. Despite these factors, Altbeton is a growing practice in sustainable construction, supported by ongoing research and evolving standards that aim to broaden the safe use of recycled concrete materials.